hw='hello world'
a='hello'
b='world'
print(a+b)

#n*x x*n 复制几分
print(a*3)

for i in hw:#list列表
    print(i)

print(hw[0:2])#0~1
print(hw[0:-1])

weekstr='星期一星期二星期三星期四星期五星期六星期日'
weekid=int(input("请输入1-7的数字"))
posstar=(weekid-1)*3
posend=posstar+3
print(weekstr[posstar:posend])
